Income Taxes (Narrative) (Details) - USD ($) |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
Operating Loss Carryforwards [Line Items] | |||
Income tax expense (benefit) related to the Tax Act | $ 19,017,000 | ||
Uncertain income tax positions | 0 | $ 249,000 | $ 0 |
Basis in partnerships | 13,377,000 | 22,922,000 | |
Deferred tax assets | 32,611,000 | 68,902,000 | |
Interest and penalties expense | 0 | 0 | $ 0 |
Accrued expenses | 0 | $ 0 | |
Federal | |||
Operating Loss Carryforwards [Line Items] | |||
Net operating loss carryforward | $ 67,000,000 | ||
Operating loss carryforward, expiration date | Dec. 31, 2029 | ||
Minnesota and Nebraska | State | |||
Operating Loss Carryforwards [Line Items] | |||
Net operating loss carryforward | $ 20,200,000 | ||
Deferred tax assets | 1,300,000 | ||
Valuation allowance | 1,300,000 | ||
Colorado | State | |||
Operating Loss Carryforwards [Line Items] | |||
Net operating loss carryforward | $ 200,000 | ||
Operating loss carryforward, expiration date | Dec. 31, 2028 |